A clamping plate structure of a building beam column reinforcing device

Abstract

The utility model provides a kind of clamping plate structure of building beam column reinforcing device belongs to clamping plate structure technical field, the clamping plate structure of this building beam column reinforcing device includes at least four arc cast iron split clamping plate, split clamping plate is arranged along the circumference of reinforced beam column and is jointly enclosed into annular coating space;The circumferential end of each split clamping plate is respectively provided with trapezoidal tenon and trapezoidal mortise, and adjacent split clamping plate is mutually inlaid in radial plane by trapezoidal tenon and trapezoidal mortise;Clamping plate structure is also provided with radial force applying component, and radial force applying component acts on the inner arc surface or outer arc surface of each split clamping plate, for simultaneously supporting open all split clamping plate in radial direction, make trapezoidal tenon and trapezoidal mortise relative slip and self-locking in radial inlaying process, to further inwardly extrude beam column original section, form annular precompression stress in beam column concrete, solve the problem that traditional welding hoop cannot avoid obstacle, need open fire operation and interface pre-tightening is easy to fail under the operation condition of subway, national railway.

Description

Technical Field

[0001] This utility model belongs to the field of clamp structure technology, specifically, it relates to a clamp structure for a building beam and column reinforcement device. Background Technology

[0002] In the underground structures of subway and national railway stations, columns and beams are the core components that bear the vibration of trains, the live load of people, and the pressure of water and soil. With the increase in traffic volume, structural aging, or adjustments to the function of underground spaces, existing beams and columns often face problems such as insufficient load-bearing capacity, rapid crack development, or decreased durability. In order to complete reinforcement without interrupting operations, the engineering community generally adopts the "section expansion" approach: adding steel or concrete sleeves around the original reinforced concrete beams and columns, thereby sharing internal forces and improving structural ductility through the added section. The sandwich structure, as the key force transmission medium for the expanded section, is responsible for tightly connecting the new shell with the original components to form an integrated load-bearing system. Traditional methods often use butt-jointed steel plates or angle steel, and complete the installation through a large number of high-strength bolts, welded hoops, or grouting non-shrink mortar. The basic process is to first arrange angle steel at the four corners of the beam and column, then weld the gusset plates or hoops horizontally, and finally pour fine stone concrete or grout to form a composite section between the old and new materials. This method is intuitive in concept and the materials are readily available, and it has become a routine method in the maintenance of subways and national railways.

[0003] However, subway and national railway stations are characterized by narrow spaces, limited ventilation, tight operating hours, and dense pre-buried pipelines, amplifying the drawbacks of traditional sandwich structures during high-frequency use. Firstly, welding operations require open flames, underground spaces have strict fire safety approvals, and welding fumes and sparks pose a threat to the safety of electromechanical equipment. Secondly, beam and column surfaces often contain obstacles such as cable supports, grounding flat steel, and fire water pipes, requiring the sealing plates to be drilled or cut on-site to avoid them, resulting in long processing cycles, reduced precision, and the cut edges easily becoming fatigue sources. Thirdly, the spliced ​​steel plates rely on friction for force transmission, and bolt preload is significantly affected by dust and moisture, making them prone to slippage under long-term train vibration, leading to a high risk of interface failure. Furthermore, transverse welds are often located in areas of maximum stress, and heat input causes degradation of the base material, making fatigue cracks prone to initiation from the weld toe. Finally, the added steel sleeve is heavy, placing additional loads on the existing floor slab. In stations with high groundwater levels and limited buoyancy tolerances in the foundation slab, further loading often requires simultaneous foundation reinforcement, creating a chain reaction of costs. Utility Model Content

[0004] In view of this, the present invention provides a clamping plate structure for a building beam and column reinforcement device, which solves the problems of traditional welded clamping plates being unable to avoid obstacles, requiring open flame operations, and being prone to interface pre-tightening failure under the conditions of subway and national railway operation, and realizes rapid cross-section expansion reinforcement without welding, capable of bypassing obstacles, and with instant self-locking pre-compression.

[0005] This utility model is implemented as follows:

[0006] This utility model provides a clamping plate structure for a building beam and column reinforcement device, comprising at least four arc-shaped cast iron segmented clamping plates. The segmented clamping plates are arranged circumferentially along the beam and column to be reinforced and together form a circumferential covering space. Each segmented clamping plate has a trapezoidal tenon and a trapezoidal mortise at both ends of its circumferential direction. Adjacent segmented clamping plates are interlocked with each other in the radial plane through the trapezoidal tenon and trapezoidal mortise to form a continuous closed tenon-mortise interlocking ring. The clamping plate structure is also provided with a radial force-applying component. The radial force-applying component acts on the inner or outer arc surface of each segmented clamping plate to simultaneously open all segmented clamping plates in the radial direction, so that the trapezoidal tenon and trapezoidal mortise can slide relative to each other and self-lock during the radial interlocking process, thereby squeezing the original cross-section of the beam and column inward and forming a ring-shaped pre-compression stress in the beam and column concrete.

[0007] The technical advantages of the clamping plate structure of the building beam and column reinforcement device provided by this utility model are as follows: Four or more arc-shaped cast iron plates form a ring around the outside of the beam and column, and are self-locked in the radial plane with trapezoidal tenons and mortises. Then, with the help of radial force application components, they are opened at one time, so that each plate applies annular pre-compression to the original concrete at the moment of insertion. This not only eliminates the large number of welding stirrups required for traditional cross-section expansion, but also enables rapid installation in narrow underground spaces, forming a self-stabilizing "outer hoop, inner pressure" structure, which significantly improves reinforcement efficiency and reduces construction disturbance.

[0008] Based on the above technical solution, the clamping plate structure of the building beam and column reinforcement device of this utility model can be further improved as follows:

[0009] The trapezoidal tenon extends tangentially along the end of the segmented clamping plate, and the trapezoidal mortise is recessed tangentially along the end of the adjacent segmented clamping plate. The inclined angle of the trapezoidal tenon and the trapezoidal mortise is consistent, and the inclined surface faces inward. This allows the inclined surfaces to slide against each other when the plate is radially expanded, generating a component force inward toward the ring, which gradually eliminates the gap between the segmented clamping plate and the surface of the beam and column.

[0010] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the trapezoidal tenon and the mortise are arranged with the same inclined plane and the inclined plane facing inward, so that when the radial expansion is achieved, the inclined plane slides and automatically generates a component force pointing towards the center of the circle, eliminating the initial gap between the plate and the beam and column point by point, realizing "sliding and tightening at the same time", avoiding eccentric gaps during installation, and ensuring that the subsequent pre-compression stress is evenly transferred to the entire section.

[0011] Furthermore, the radial force application component includes multiple jacks evenly distributed around the circumference. The fixed end of each jack abuts against the inner arc surface of a segmented clamping plate, and the movable end abuts against the inner arc surface of the opposite segmented clamping plate. The extension and retraction direction of the jacks is set along the circumferential diameter direction, and the radial expansion of all segmented clamping plates is achieved through synchronous extension.

[0012] The beneficial effects of adopting the above-mentioned improved scheme are as follows: several jacks can be used to directly push the opposite side plate along the diameter direction. All jacks can be supplied with oil simultaneously. The operation is simple and the thrust is intuitively visible. Moreover, the jack body itself serves as a temporary support. After installation, it can be directly locked or removed under pressure without the need for additional fixing clamps. This significantly simplifies the construction process and shortens the downtime.

[0013] Furthermore, the radial force application component includes an annular hydraulic bladder sleeved around the outer periphery of the segmented clamping plate. After being filled with fluid, the hydraulic bladder expands uniformly inward, and its inner surface fits the outer arc surface of each segmented clamping plate. Through hydraulic pressure, each segmented clamping plate is pushed synchronously into the ring, thereby achieving radial expansion and tenon-and-mortise engagement.

[0014] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the ring-shaped hydraulic bladder is wrapped around the outer periphery and expands evenly inward after being filled with liquid, so that the force on each plate is consistent, which can avoid the problem of uneven jacking force that may occur with multi-point jacks. It is especially suitable for old cylinders with slight ellipticity. Its flexible bladder wall can adapt to irregular shapes, ensuring that the tenon and mortise are tightly fitted and that no indentations are generated in local areas.

[0015] Furthermore, the inner arc surface of the segmented clamp is provided with continuous protruding teeth, which extend axially and are distributed circumferentially to embed into the beam and column surface during radial compression, forming additional shear-resistant mechanical engagement.

[0016] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the continuous convex teeth on the inner arc surface of the plate slightly embed into the surface of the beam and column when radially compressed, forming a mechanical interlock with the concrete and directly bearing the longitudinal shear. This allows the expanded section and the original component to work together without waiting for the grout to harden, achieving "immediate load-bearing upon installation", which is especially crucial for the Qingdao North Railway Station underground passage that needs to be quickly restored to operation.

[0017] Furthermore, the outer arc surface of the segmented clamp is provided with an axially penetrating reinforcing rib. The cross-sectional height of the reinforcing rib gradually decreases radially outward from the outer arc surface. This is used to improve the circumferential stiffness of the segmented clamp while maintaining lightweight design, and to prevent circumferential bending deformation during the slippage of the tenon and mortise joints.

[0018] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the gradually increasing reinforcing ribs on the outer arc surface improve the circumferential stiffness of the plate without significantly increasing its own weight, prevent the plate from bulging outward due to the concentration of reaction force during the mortise and tenon slippage stage, thereby keeping the tenon and mortise axis aligned, ensuring a smooth self-locking process, and reducing installation stress loss.

[0019] Furthermore, the mating surfaces of the trapezoidal tenon and the trapezoidal mortise are provided with mirror-image micro-serrations. The tooth tip direction of the micro-serrations is perpendicular to the inclined direction of the inclined surface, which is used to provide reverse self-locking when the tenon and mortise are finally engaged, preventing the trapezoidal tenon from slipping out in the reverse direction after unloading.

[0020] The mating surfaces of the trapezoidal tenon and the trapezoidal mortise are provided with mirror-image micro-serrations, specifically configured as follows:

[0021] The micro-serrations are continuously distributed along the mating surface of the trapezoidal tenon and the trapezoidal mortise, with the tooth height being less than the surface roughness and the tooth shape being an isosceles triangle;

[0022] The tooth tip of the micro-serration is perpendicular to the direction of the inclined plane, which is used to provide reverse self-locking when the tenon and mortise are in the final position.

[0023] The tooth pitch of the micro-serrations is less than the mating length between the trapezoidal tenon and the trapezoidal mortise, ensuring that the micro-serrations can interlock during the fitting process and preventing the trapezoidal tenon from slipping off in the reverse direction after unloading.

[0024] Furthermore, the segmented clamp is divided into at least two segments in the axial direction, and the adjacent segments are connected by axial tenon joints, so that the entire clamp structure can be spliced ​​along the axial direction to adapt to different beam and column heights, and the axial insertion direction is perpendicular to the circumferential trapezoidal tenon direction to form a three-dimensional interlocking grid.

[0025] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the slab is made into a multi-segment interlocking form along the axial direction, and the segments can be quickly added or removed on site according to the height of the beams and columns. The axial interlocking and the circumferential tenon and mortise are perpendicular to each other to form a three-dimensional grid, which makes the force flow at the joint smooth. This not only facilitates transportation, but also solves the common problems of uneven floor height and local obstacles in underground spaces, realizing "modular assembly".

[0026] Furthermore, the clamping structure also includes a thin-walled flexible liner between the segmented clamping plate and the beam / column surface. The liner is wavy when not compressed, and is flattened and fills the unevenness and defects on the beam / column surface during radial expansion, so as to ensure uniform stress transmission while forming annular prestress.

[0027] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the corrugated thin-walled flexible liner has a pre-reserved deformation margin before extrusion, and automatically fills the pitted surface, honeycomb or old bolt holes on the original component surface after flattening, avoiding stress concentration at high points, and at the same time playing a sealing role to prevent leakage of grout in the later stage; its elastic shrinkage can also absorb the micro-deformation of concrete shrinkage, maintain the tightness of the interface, and improve durability.

[0028] Furthermore, the number of the segmented clamps, the distribution of the trapezoidal tenons and mortises, and the arrangement of the radial force-applying components are configured to bypass existing obstacles in the beams and columns, so that some of the segmented clamps are offset in the axial direction to form an asymmetrical circumferential covering.

[0029] The number of the segmented clamping plates, the distribution of the trapezoidal tenons and mortises, and the arrangement of the radial force-applying components are configured to bypass existing obstacles in the beams and columns, allowing some of the segmented clamping plates to be axially offset to form an asymmetrical circumferential covering. The specific configuration is as follows:

[0030] The number of segmented clamps is determined based on the perimeter of the beam and column and the location of obstacles, and includes at least four arc-shaped cast iron segmented clamps, some of which are offset axially to avoid pre-embedded bolts or protruding structures on the beam and column.

[0031] The distribution positions of the trapezoidal tenon and trapezoidal mortise are adjusted accordingly on the staggered split clamp to ensure that the trapezoidal tenon and trapezoidal mortise can still fit together in the radial plane after axial misalignment.

[0032] The arrangement of the radial force application components is adjusted according to the position of the misaligned segmented clamps to ensure that all segmented clamps are opened simultaneously in the radial direction, achieving asymmetrical circumferential coverage.

[0033] Compared with existing technologies, the beneficial effects of the clamp structure of the building beam and column reinforcement device provided by this utility model are as follows: The segmented tenon and mortise clamp expansion system proposed by this utility model, with the core concept of "radial expansion - tenon self-locking - circumferential pre-stressing", transforms the passive constraint of the traditional "grouting after welding" into a mechanical process of actively applying circumferential compressive stress, fundamentally overcoming the limitations of existing reinforcement technologies in subway and national railway station environments. First, the entire system is composed entirely of mechanical interlocking and frictional force transmission, requiring no on-site welding or open flame operations, eliminating fire risks in underground spaces, and saving welding quality inspection and rework time, allowing for full utilization of short nighttime windows for construction; second, the segmented structure is prefabricated as arc-shaped units in the factory and installed on-site in the order of "first positioning, then expansion". When encountering pre-embedded bolts or pipelines, the corresponding segments only need to be axially offset to naturally form a discontinuous wrapping that avoids obstacles, eliminating the need for on-site drilling, welding, or cutting, maintaining structural integrity, and significantly shortening the processing and installation cycle; third, During radial sliding, the trapezoidal tenon and mortise generate a component force pointing towards the center, causing each segment to simultaneously grip the beam and column. Initial gaps at the interface are gradually eliminated, avoiding the pre-tightening loss caused by initial gaps in traditional clamping plates. Stable circumferential preload is provided instantly upon installation, achieving "immediate load-bearing upon installation." Vibrations and fatigue cycles generated by train operation the following day are effectively suppressed under the pre-stress field, significantly reducing the risk of crack propagation and interface slippage. Furthermore, the micro-serrations on the tenon and mortise mating surfaces form a reverse mechanical lock at the final engagement position, ensuring that even if concrete shrinkage or temperature deformation occurs later, the tenon will not... The self-slippage mechanism is equivalent to adding "anti-racket teeth" to the entire reinforcement ring, significantly improving long-term reliability. The thin-walled flexible liner is wavy before compression and automatically fills the pitted surface, honeycomb, and old bolt holes after compression, which not only prevents local stress concentration but also plays a role in sealing and corrosion prevention, which is especially important for coastal high-humidity and high-salt environments like Qingdao North Station. The gradually increasing reinforcing ribs on the segmented outer arc surface improve the circumferential stiffness of the unit without significantly increasing its own weight, so that the segments maintain an ideal arc during the expansion process, avoiding outward bulging deformation that causes the tenon axis to shift, thereby ensuring a smooth self-locking process and minimal prestress loss. The axial multi-segment plug-in design allows the system to extend freely with the height of the beams and columns like "building blocks." Transportation and handling can be completed in narrow passages. The assembly joints naturally form a force flow transition due to the mutually perpendicular three-dimensional tenon and mortise grid, without the need for additional cover plates or weld reinforcement. Ultimately, the entire reinforced body forms a continuous annular pressure hoop, and the original beam and column concrete is under triaxial compression. Its axial compressive performance and fatigue life are improved simultaneously. The shell composed of the newly added cast iron segments and the subsequent optional grouting layer provides additional bending stiffness and durability barrier, achieving a comprehensive enhancement of load-bearing capacity, ductility, and service life. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 An example diagram of a clamping plate structure for a building beam and column reinforcement device;

[0036] Figure 2 A side view of a clamping plate structure for a building beam and column reinforcement device;

[0037] Figure 3 This is a diagram illustrating the splicing of a clamping structure for a building beam and column reinforcement device.

[0038] The attached diagram lists the components represented by each number as follows:

[0039] 10. Split-plate; 11. Trapezoidal tenon; 12. Trapezoidal mortise; 20. Radial force application component. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0041] like Figure 1 , Figure 2 The diagram shows an example of a clamping plate structure for a building beam and column reinforcement device provided by this utility model: it includes at least four arc-shaped cast iron segmented clamping plates 10, which are arranged circumferentially along the beam and column to be reinforced and together form a circumferential covering space; each segmented clamping plate 10 has a trapezoidal tenon 11 and a trapezoidal mortise 12 at both ends of its circumferential direction, and adjacent segmented clamping plates 10 are interlocked with each other in the radial plane through the trapezoidal tenon 11 and the trapezoidal mortise 12 to form a continuous closed tenon and mortise interlocking ring; the clamping plate structure also has a radial force application component 20, which acts on the inner arc surface or outer arc surface of each segmented clamping plate 10 to simultaneously open all segmented clamping plates 10 in the radial direction, so that the trapezoidal tenon 11 and the trapezoidal mortise 12 will slide relative to each other and self-lock during the radial interlocking process, thereby squeezing the original cross section of the beam and column inward and forming a ring-shaped pre-compression stress in the beam and column concrete.

[0042] like Figure 3 As shown, each segmented clamp can be made with only "one section of height". If you want to increase the height, you can stack another section on top. The two sections are connected by a plug, that is, a rectangular protrusion extends from one end face, and a rectangular groove is opened on the other end face. The protrusion is inserted into the groove, and the height is stacked like building blocks.

[0043] In the above technical solution, the trapezoidal tenon 11 extends tangentially along the end of the segmented clamping plate 10, and the trapezoidal mortise 12 is recessed tangentially along the end of the adjacent segmented clamping plate 10. The inclined angles of the trapezoidal tenon 11 and the trapezoidal mortise 12 are consistent, and the inclined surfaces face inwards, so that when the radial expansion is achieved, the inclined surfaces slide against each other and generate a component force facing inwards, gradually eliminating the gap between the segmented clamping plate 10 and the beam / column surface.

[0044] Furthermore, in the above technical solution, the radial force application component 20 includes multiple jacks evenly distributed around the circumference. The fixed end of the jack abuts against the inner arc surface of a segmented clamping plate 10, and the movable end abuts against the inner arc surface of the opposite segmented clamping plate 10. The extension and retraction direction of the jacks is set along the circumferential diameter direction, and the radial expansion of all segmented clamping plates 10 is achieved by synchronous extension.

[0045] Furthermore, in the above technical solution, the radial force application component 20 includes an annular hydraulic bladder sleeved on the outer periphery of the segmented clamping plate 10. After being filled with liquid, the hydraulic bladder expands inward evenly, and its inner surface fits the outer arc surface of each segmented clamping plate 10. Through hydraulic pressure, each segmented clamping plate 10 is pushed into the ring simultaneously to achieve radial expansion and tenon-and-mortise engagement.

[0046] Furthermore, in the above technical solution, the inner arc surface of the split clamp 10 is provided with continuous convex teeth, which extend axially and are distributed circumferentially, for embedding into the beam and column surface during radial compression to form additional shear-resistant mechanical interlocking.

[0047] Furthermore, in the above technical solution, the outer arc surface of the segmented clamping plate 10 is provided with an axially penetrating reinforcing rib. The cross-sectional height of the reinforcing rib gradually decreases from the outer arc surface radially outward, which is used to improve the circumferential stiffness of the segmented clamping plate 10 while maintaining lightweight, and to prevent circumferential bending deformation during the mortise and tenon slippage process.

[0048] Furthermore, in the above technical solution, the mating surfaces of the trapezoidal tenon 11 and the trapezoidal mortise 12 are provided with mirror-image micro-serrations. The tooth tip direction of the micro-serrations is perpendicular to the inclined direction of the inclined surface, which is used to provide reverse self-locking when the tenon and mortise are in the final position, preventing the trapezoidal tenon 11 from slipping out in the reverse direction after unloading.

[0049] The micro-serration has an isosceles triangle shape with a 60° apex angle, a tooth height of 0.3 mm, a tooth pitch of 0.8 mm, and a root radius of 0.05 mm. The dimensions are continuously and evenly distributed along the entire mating surface of the trapezoidal tenon 11 and the trapezoidal mortise 12, and the same tooth shape parameters are maintained within 3 mm of the edge of the mating surface to ensure consistent reverse self-locking performance.

[0050] Furthermore, in the above technical solution, the segmented clamping plate 10 is divided into at least two segments in the axial direction, and the adjacent two segments are connected by axial tenon and mortise joints, so that the entire clamping plate structure can be spliced ​​along the axial direction to adapt to different beam and column heights, and the axial insertion direction is perpendicular to the circumferential trapezoidal tenon and mortise direction to form a three-dimensional interlocking grid.

[0051] Furthermore, in the above technical solution, the clamping structure also includes a thin-walled flexible liner between the segmented clamping plate 10 and the surface of the beam and column. The liner is wavy when it is not compressed, and is flattened and fills the unevenness and defects on the surface of the beam and column during the radial expansion process, so as to ensure uniform stress transmission while forming annular prestress.

[0052] The thin-walled flexible liner is made of ethylene propylene diene monomer (EPDM) rubber and aramid fiber composite sheet, in which the aramid fiber is embedded in the EPDM matrix in a mesh pattern with a mesh size of 2mm×2mm; it is suitable for underground high-humidity and high-salt environments.

[0053] Furthermore, in the above technical solution, the number of segmented clamping plates 10, the distribution of trapezoidal tenons 11 and trapezoidal mortises 12, and the arrangement of radial force-applying components are configured to bypass existing obstacles in the beams and columns, so that some of the segmented clamping plates 10 are misaligned in the axial direction to form an asymmetrical circumferential covering.

[0054] First Example: Rapid Reinforcement Project for Column Foundations in an Underground Parking Lot of a Railway Station: A section of the underground parking lot at a coastal railway station, originally designed for small passenger vehicles, needed to be converted into an equipment room. This necessitated an increase in the load-bearing capacity of four 600mm diameter frame columns. The nearby fire water tank room still needed to be used during the day, only closed from midnight to 5 AM. Furthermore, fire sprinkler mains and cable trays were already installed around the columns, making welding impossible and large-scale pipeline removal prohibited. After research, the design department and design unit decided to use this utility model's "segmented tenon-and-mortise joint expansion system" to complete the reinforcement.

[0055] The factory prefabricates six ductile iron sections according to the column diameter, each with a central angle of 60 degrees and an axial height of 300 millimeters. The inner radius of the section matches the outer circle of the column. Trapezoidal tenons and mortises are milled at both ends, with a 15-degree bevel angle. The mating surfaces are rolled with micro-serrations at a 60-degree apex angle to form a unidirectional anti-reverse structure. A "ridge"-shaped gradually rising reinforcing rib is cast along the axial direction in the middle of the outer arc surface. The rib top reaches the thickest part of the plate at 12 millimeters, and then smoothly tapers to 6 millimeters at the upper and lower edges, ensuring circumferential stiffness while reducing self-weight. A 0.5-millimeter-thick corrugated EPDM-aramid composite liner with a corrugation height of 2 millimeters is bonded to the inner side of the section with structural adhesive. Under pressure, it can expand to fill the pits on the column surface.

[0056] During nighttime construction, workers first removed the column base anti-collision plates, leaving the sprinkler pipes in place. Six segmented panels were then placed around the column, with two panels raised 150 mm below the cable tray to create axial misalignment and successfully avoid obstacles. The trapezoidal tenons of adjacent segments remained on the same horizontal plane to ensure reliable fitting. Next, ultra-thin manual hydraulic pillows were placed in the pre-reserved recesses on the inner arcs of the two segments at a 120-degree angle to each other, with a 20 mm stroke. Pressurized by a synchronous pump, both pillows simultaneously extended outwards, causing the six segments to move radially outwards. The trapezoidal slopes slid against each other, the ridge ribs prevented the panels from bulging, and the corrugated lining was flattened point by point and squeezed into the gaps in the old column's mortar. When the pillows reached their designated stroke, the micro-serrations engaged and locked themselves in place. After depressurization, a hammer test confirmed no springback, thus completing the first ring.

[0057] Following the same steps, the second and third rings are stacked upwards, each staggered by 90 degrees to form a quincunx pattern. The upper and lower rings are connected axially using male and female connectors with end faces; the connectors are 20 mm long and automatically align upon insertion, requiring no additional bolts. The entire column consists of ten stacked rings, reaching a total height of three meters, with construction time controlled within four hours. Finally, additional longitudinal threaded steel bars are tied to the outer arc of the slab, and polymer-modified mortar is sprayed to form a 40 mm thick outer layer. The old and new sections immediately share the load under circumferential pre-compression. The parking lot reopens at 5:00 AM, and buses can park normally.

[0058] Second embodiment: A second-floor underground frame beam of a subway station, 500 mm wide and 800 mm high, developed longitudinal cracks at the bottom mid-span due to long-term heavy load fatigue. It was necessary to improve its bending resistance without interrupting train arrival and departure lines. The clearance between the beam bottom and the base slab was only 300 mm, and the side walls housed signal cable trays, making it impossible to install large jacks or weld closed steel plates. A modified version of the segmented tenon-and-mortise clamping system of this utility model was adopted: the factory changed the clamping plates to two horizontal segments on each side, still made of ductile iron, with trapezoidal tenons placed at the horizontal joints, and the inner arc curvature customized according to the beam width; each segment had an axial length of 1000 mm, and was slid horizontally into place on site along both sides of the cable tray, leaving a gap directly below the tray to form an "open hoop". An ultra-thin hydraulic bladder was inserted between the beam side and the segments, and simultaneously filled with oil. The two segments moved horizontally outward, the trapezoidal tenons self-locked, and the lining pressed against the cracked area. Subsequently, additional longitudinal reinforcement was tied on-site to the outer arc of the segments, and polymer-modified mortar was sprayed to form a continuous composite layer extending 80 mm outward. The entire operation was completed in two sessions within the train's operating interval, each lasting two hours. No open flame was required, and no cables were touched. The cracks at the bottom of the beam were closed under the combined action of circumferential preloading and the newly added composite layer, significantly improving the bending stiffness. This method is suitable for repairing fatigue cracks in underground frame beams of subways and national railways with low clearance, obstacles, and inability to be vertically supported.

[0059] Specifically, the principle of this utility model is as follows: Based on the triple coupling effect of mechanical expansion, shape self-locking and interface pre-compression, this utility model utilizes the elasticity and rigid-plastic deformation coordination of the segmented cast iron clamp to construct a self-supporting prestressed hoop shell around the beam and column. First, from a mechanical perspective, the radial force-applying component pushes each segment outward simultaneously, and the trapezoidal tenon slides relative to the corresponding mortise slope. The sliding direction forms a fixed angle with the slope normal. According to the law of force decomposition, the radial thrust is converted into a positive pressure perpendicular to the slope and a tangential component force downward along the slope. The positive pressure causes a sharp increase in the frictional resistance of the contact surface, while the tangential component force continuously pulls the segments inward, forming a self-locking effect of "the more it is supported, the tighter it becomes". When the sliding reaches the designed stroke, the micro-serrations of the mating surface mesh with each other, and the reverse sliding is mechanically blocked. The system enters a stable self-balancing state. At this time, the beam and column surfaces are subjected to uniformly distributed radial pressure. The original concrete changes from unidirectional or bidirectional force to triaxial compression. Its cracking tendency is suppressed by the circumferential compressive stress field, and the fatigue performance is improved accordingly. Secondly, from the perspective of structural compatibility, the segmented units are prefabricated using arc segments. The curvature of the inner arc is consistent with the theoretical cylindrical surface, and the cross-sectional modulus increases after the addition of gradually increasing ribs to the outer arc. However, the height of the rib top decreases along the tangent direction of the arc, so that the unit maintains an approximately equal strength beam state during the expansion process, avoiding local warping that could cause the tenon and mortise to jam. Adjacent axial segments are vertically fitted together through male and female interlocking joints. The direction of the interlocking joints is spatially orthogonal to the circumferential trapezoidal tenon and mortise, forming a three-dimensional grid. Force flow can be seamlessly transmitted in the circumferential and axial directions without the need for additional welds or cover plates. Thirdly, from the perspective of interface matching, the corrugated flexible liner provides point support in the initial state. After being compressed, the crests flatten out, and the principle of material volume conservation causes it to expand laterally, automatically filling the concave areas and transforming point contact into surface contact, significantly reducing the stress concentration coefficient. The liner material is a salt spray resistant rubber-fiber composite material, whose elastic modulus is lower than that of concrete but higher than that of most sealants. It can adapt to micro-deformation and absorb shear slip energy in vibration environments, playing a dual role of damping and corrosion protection. Finally, from the perspective of construction controllability, the entire system is completed through purely mechanical steps: segmented positioning, axial misalignment to avoid obstacles, radial synchronous expansion, tenon self-locking, and removal of hydraulic pressure or jacks. The entire process only requires a torque wrench or manual pump, without the need for power supply, heat source or large machinery. Construction errors are self-digested through the "sliding-aligning-locking" mechanism of trapezoidal inclined plane and micro-serrations. The installation quality is intuitively visible, and later maintenance can also be carried out by loosening the tenon with reverse small displacement to achieve quick disassembly and reuse.

Claims

1. A clamping plate structure for a building beam and column reinforcement device, characterized in that: The structure includes at least four arc-shaped cast iron segmented clamps, which are arranged circumferentially along the beam and column being reinforced and together form a circumferential enclosing space. Each segmented clamp has a trapezoidal tenon and a trapezoidal mortise at both ends of its circumferential direction. Adjacent segmented clamps are interlocked in the radial plane through the trapezoidal tenon and mortise to form a continuous closed tenon-mortise interlocking ring. The clamp structure also includes a radial force-applying component, which acts on the inner or outer arc surface of each segmented clamp to simultaneously open all segmented clamps in the radial direction. This causes the trapezoidal tenon and mortise to slide relative to each other and self-lock during the radial interlocking process, thereby compressing the original cross-section of the beam and column inward and forming a circumferential prestress in the beam and column concrete.

2. The clamping plate structure of the building beam and column reinforcement device according to claim 1, characterized in that, The trapezoidal tenon extends tangentially along the end of the segmented clamping plate, and the trapezoidal mortise is recessed tangentially along the end of the adjacent segmented clamping plate. The inclined angle of the trapezoidal tenon and the trapezoidal mortise is consistent, and the inclined surface faces inward. This allows the inclined surfaces to slide against each other when the plate is radially expanded, generating a component force inward toward the ring, which gradually eliminates the gap between the segmented clamping plate and the surface of the beam and column.

3. The clamping plate structure of the building beam and column reinforcement device according to claim 2, characterized in that, The radial force application component includes multiple jacks evenly distributed around the circumference. The fixed end of each jack abuts against the inner arc surface of a segmented clamping plate, and the movable end abuts against the inner arc surface of the opposite segmented clamping plate. The extension and retraction direction of the jacks is set along the circumferential diameter direction, and the radial expansion of all segmented clamping plates is achieved through synchronous extension.

4. The clamping plate structure of the building beam and column reinforcement device according to claim 2, characterized in that, The radial force application component includes an annular hydraulic bladder sleeved around the outer periphery of the segmented clamping plates. After being filled with fluid, the hydraulic bladder expands uniformly inward, and its inner surface fits the outer arc surface of each segmented clamping plate. Through hydraulic pressure, each segmented clamping plate is pushed synchronously into the ring, thereby achieving radial expansion and tenon-and-mortise engagement.

5. The clamping plate structure of a building beam and column reinforcement device according to any one of claims 3 or 4, characterized in that, The inner arc surface of the segmented clamp is provided with continuous convex teeth, which extend axially and are distributed circumferentially to embed into the beam and column surface during radial compression, forming additional shear-resistant mechanical interlocking.

6. The clamping plate structure of the building beam and column reinforcement device according to claim 5, characterized in that, The outer arc surface of the segmented clamp is provided with an axially penetrating reinforcing rib. The cross-sectional height of the reinforcing rib gradually decreases radially outward from the outer arc surface. This is used to improve the circumferential stiffness of the segmented clamp while maintaining lightweight design, and to prevent circumferential bending deformation during the slippage of the tenon and mortise joints.

7. The clamping plate structure of the building beam and column reinforcement device according to claim 6, characterized in that, The mating surfaces of the trapezoidal tenon and the trapezoidal mortise are provided with mirror-image micro-serrations. The tooth tip direction of the micro-serrations is perpendicular to the inclined direction of the inclined surface, which is used to provide reverse self-locking when the tenon and mortise are finally engaged, preventing the trapezoidal tenon from slipping out in the reverse direction after unloading.

8. The clamping plate structure of the building beam and column reinforcement device according to claim 7, characterized in that, The segmented clamp is divided into at least two sections in the axial direction. The two adjacent sections are connected by axial tenon and mortise joints, so that the entire clamp structure can be spliced ​​along the axial direction to adapt to different beam and column heights. The axial insertion direction is perpendicular to the circumferential trapezoidal tenon and mortise direction, forming a three-dimensional interlocking grid.

9. The clamping plate structure of the building beam and column reinforcement device according to claim 8, characterized in that, The clamping structure also includes a thin-walled flexible liner between the segmented clamping plate and the beam / column surface. The liner is wavy when not compressed, and is flattened and fills the unevenness of the beam / column surface during radial expansion, so as to ensure uniform stress transmission while forming circumferential prestress.

10. The clamping plate structure of the building beam and column reinforcement device according to claim 9, characterized in that, The number of the segmented clamps, the distribution of the trapezoidal tenons and mortises, and the arrangement of the radial force-applying components are configured to bypass existing obstacles in the beams and columns, so that some of the segmented clamps are offset in the axial direction to form an asymmetrical circumferential covering.

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